How Fast Will Leon Marchand Swim 400 IM at World Championships?

Coming off an historic NCAA performance, Leon Marchand won four races at the Pro Swim in Westmont. That included blasting a 1:55.68 200 IM, breaking Michael Phelps’ Pro Swim Record and eclipsing the 400 IM Pro Swim Record in 4:07.80.

Leon took five days off after NCAA Championships, but got back into hard work quickly under coach Bob Bowman.  Leon was happy with his 1:55 200 IM and 4:07 400 IM at the Pro Swim before heading into intense altitude training at the Olympic Training Center (OTC).

In this interview he unpacks going back to France to train under his old coach, what he’s focused on swimming at World Championships, and where he hopes to be a factor on French relays at World Champs.

Leon Marchand 400 IM World Championship Predictions!

I’m only playing because my NCAA Championships 400 IM prediction was so anemic. I predicted a 3:30.09, noting in the comments that my brain could not go below a 3:30.00…and he, of course, ripped a 3:28.82.

Michael Phelps’ 2008 super-suited 4:03.84 feels like a weak line in the sand against Marchand, but how weak? I tried our time converter, but the converter has been hit or miss in the past, largely due to yards-underwater-dolphin-kicking. (Still, a lot of  World and Olympic medalists do convert better with our converter than those off the medal podium.)  For a 3:28.82 the converter gave me an eye-popping 3:58.19! I know, that’s a crazy prediction, but maybe it’s in range.  Consider that Marchand was a 3:34.08 at NCAA Champs in 2022, and he was a 4:04.28 in meters at the 2022 World Champs.   Is a nearly six second drop on the horizon?

After my weak NCAA prediction, I’m going for it!  I predict a 3:59.59, a mind-melting performance (and I can hear Rowdy’s passionate screams as I write this). But who cares what I think? It’s all about what you think. Drop your comments below.

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Opinions, beliefs and viewpoints of the interviewed guests do not necessarily reflect the opinions, beliefs, and viewpoints of the hosts, SwimSwam Partners, LLC and/or SwimSwam advertising partners.

This is a Gold Medal Media production presented by Host Gold Medal Mel Stewart is a 3-time Olympic medalist and the co-founder of, a Swimming News website.

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18 days ago

Why is he being allowed to stray from Bowman, the man who got helped him to glory?

Lap counter
Reply to  Orange
16 days ago

You do realize he was two time Olympic finalist in High School? Not many guys have that on their resume! Bowman made him better but he was already VERY, VERY good!

27 days ago



27 days ago

What a bloody picture, could be the caption for a Titus Andronicus play. I say 4:02

27 days ago

Let’s 4:03.52

phelps swims 200 breast rio
27 days ago

4:03.3 2023
4:01.7 2024

Some Strange Dude
28 days ago

4:02.7 this summer at worlds. 4:01.0 at the 2024 Olympics. We’re not ready for a sub 4:00 4IM just yet.

28 days ago

He will wait until next year to obliterate the WR int he 400 IM – he will be the biggest star at the Paris Games 🙂

Golden Summer
Reply to  Kim
27 days ago

Summer McIntosh begs to differ.

Reply to  Golden Summer
27 days ago

They’ll be about equal. Leon breaking Phelps’ last record is definitely a bigger story for the public than anything summer could do.

Currently number 1&2, depending on what Popovici does and if ledecky gets her 4th straight 800, which is likely

Argentina on top 🇦🇷
Reply to  Ragnar
27 days ago

Equal, what are you talking about? This is LCM, not bathtubs.

In LCM, Leon can only win 2 golds (The IMs) like Popovici (100,200free).
Summer operates in a different league. She can win 5 individual golds in Paris. This is Phelps’s territory my friend.

You mentioned the record: Milak destroyed Phelps’ 200 fly record in 2019, it was historical BUT the star of Gwangju was Dressel because he won 4 individual golds.

Last edited 27 days ago by Argentina on top 🇦🇷
Reply to  Argentina on top 🇦🇷
27 days ago

You can be right, depends on the the number or the difference. And what Dressel will win next time? Never forget I like him, but come on. 50 fly? 50 free? 100 free is Popovici’s 100 fly who knows. And 50 fly is not at OGs.

Eric Angle
Reply to  Argentina on top 🇦🇷
25 days ago

You might be underestimating Marchand in the 200 fly and 200 breast (he won’t be able to swim it in Fukuoka, but he will be able to swim it in Paris). Not saying he’ll necessarily get gold, but surely he’s a threat, especially in the 200 breast.

Reply to  Ragnar
27 days ago

Or 1.49 200 fly e.g.

28 days ago

I am a huge leon fan — but 4:03.83 would STILL be one of the most legendary swims in history so lets not devalue it if he goes 4:02 (which is NUTS) and not 3:59 (which is fun bc its an epic barrier)

About Gold Medal Mel Stewart

Gold Medal Mel Stewart

MEL STEWART Jr., aka Gold Medal Mel, won three Olympic medals at the 1992 Olympic Games. Mel's best event was the 200 butterfly. He is a former World, American, and NCAA Record holder in the 200 butterfly. As a writer/producer and sports columnist, Mel has contributed to Yahoo Sports, Universal Sports, …

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